The jurisdiction of a court of equity to decree appropriate relief, where it appears that a bilateral contract, whether it remains executory or has been fully performed by the plaintiff, has been entered into through the fraudulent representations of the defendant, or under mutual and material errors of fact, and the bill is seasonably brought upon discovery of the fraud or mistake, is well settled. Long v. Athol, 196 Mass. 497, 501. J. P. Eustis Manuf. Co. v. Saco Brick Co. 198 Mass. 212. United Zinc Co. v. Harwood, 216 Mass. 474, 477, 478. The question for decision is whether the plaintiffs’ bill states a case within this doctrine.
The material statements admitted by the demurrer close with the allegations, that in inducing the plaintiffs to enter into the contract the defendant either intentionally perpetrated a fraud by representing that the work to be done within the stipulated time was substantially less in amount and of a substantially different *359character from the work it intended to require, and that this deception was practiced for the purpose of obtaining more favorable prices, than could have been obtained if the facts had been fully disclosed, or that the contract, which is inequitable and unconscionable under the conditions averred, was entered into by the parties under a mutual mistake of fact.
The bill is brought after full performance to the satisfaction of the city, and upon their own showing the plaintiffs seemingly must have discovered during the progress of the work the alleged discrepancies between the requirements as understood by them and the construction of the contract asserted by the city, hereafter referred to as the defendant. The contract of course could not be concurrently valid and voidable. If upon being aware of the alleged fraud they chose to go on, their conduct would justify the defendant’s contention that they affirmed the validity of the contract. Plympton v. Dunn, 148 Mass. 523. Ginn v. Almy, 212 Mass. 486, 493. But under the explanatory and charging allegations, that because of their gradual development they did not realize and appreciate the importance and effect of the differences or changes until after the work had been done and the final measurements ascertained, we shall consider the grounds upon which they rely for rescisión in the order stated in the bill, even if in view of all the alternative and qualifying allegations it seems doubtful whether actual fraud has been charged.
The plaintiffs describe themselves as engaged in the business of general contractors, and as such they have entered into and performed contracts for the construction of railroads, waterworks, reservoir dams and other works of a public nature. It was in the light of this experience that they read the pamphlet entitled, “Information for Bidders,” and the draft of “a proposed contract to be entered into by any successful bidder,” furnished by the defendant when it decided to construct an additional dam and storage reservoir in connection with its system of water supply, and advertised for bids. We assume that the proposal submitted to the plaintiffs, who were successful bidders, followed the form shown by the exhibit annexed to the bill. It contains these significant words, "The undersigned, as bidder, declares that ... he has carefully examined the location of the proposed work, the annexed proposed form of contract, and the plans and speci*360fications therein referred to; and he proposes, and agrees if this proposal is accepted, that he will contract with said City . . ., in the form of the copy of the contract deposited in the office of the” city clerk. And the contract executed by the parties recites in the twenty-fifth article that all plans, general and detail, all specifications, the information for bidders and the proposal of the contractor, “are hereby made parts of this contract.” If, as alleged, when full performance of the work as stipulated was demanded by the defendant, the plaintiffs in removing the soil for the reservoir site were compelled to excavate more than double the number of cubic yards shown by the engineer’s estimate, and in building the dam the different classes of cyclopean masonry and concrete blocks had to be furnished in greater and substituted quantities differing from the estimate, the allegations that the estimates having been well considered represented substantially the amount and character of the work and materials required, which could not be exceeded by the defendant, cannot be sustained. The engineer’s estimates for the yardage of the excavations appear in the information for bidders under the title of “approximate quantities.” The schedule of items which includes the various classes of work, masonry and materials is followed by the statement that the quantities are approximate only, and are given as a basis for the uniform comparison of bids, while the city does not either expressly or by implication agree, that the actual amount of work or materials will correspond therewith, and the right is reserved to increase or decrease the quantity of any class or portion of the work as may be deemed necessary by the engineer. The plaintiffs without the schedule before them could not have bid intelligently. If they chose to read only a part, the defendant is not responsible for their inadvertence! If they read the whole, they acted with full knowledge of the conditions under which they were bidding, and the field was open to all competitors with no favors. The averment, that because of the frost and winter weather they were unable to examine thoroughly the physical conditions underlying the surface might have been a good reason for not bidding, although the defendant required bids to be submitted during the month of December, but it is not a reason for abrogating the contract into which they voluntarily entered.
*361The last ground of avoidance is the change of the diversion conduit from the location shown by the general plan to a “Revised Approximate Location” requiring for its construction a different kind of material with a larger amount of excavation and masonry as averred in the eighteenth and twenty-first paragraphs of the bill. The plaintiffs’ attention had been called to the change when the parties met to complete the contract, and before its execution. While the plaintiffs allege that the defendant “ through its engineer thereunto duly authorized” represented that the change in the line and grade would not involve additional expense, it is not alleged that the representations were made for the purpose of misleading them. If as general contractors of wide knowledge and large ability they preferred to rely on the engineer’s statements instead of acting on their own judgment, informed by the general plan, the conduit plan and profile, which were before them, where the outline of the revised and approximate location plainly appears showing the old line “along the edge of the upland” when they bid, and the increased length of the new line drawn “nearer the brook,” and without further inquiry or examination executed the contract, they are not shown to have been overreached by the conduct of the defendant. The plaintiffs cannot shut their eyes to the facts and contend that they were misled or defrauded. Mabardy v. McHugh, 202 Mass. 148, 151, and cases cited. King v. Eagle Mills, 10 Allen, 548, 551. Keene v. Demelman, 172 Mass. 17.
It furthermore is not alleged that the engineer had authority to do away with the contract which the parties had met to execute, and, whether what was said by him amounted to a collateral contract binding on the defendant, is not before us. The bill seeks only to cancel the contract which the plaintiffs signed.
It is also apparent that the contract is not based on a material mistake shared by both parties as in Long v. Athol, 196 Mass. 497. To warrant the reformation of a written instrument for mistake the real intention of the parties must be clearly established. German American Ins. Co. v. Davis, 131 Mass. 316. J. P. Eustis Manuf. Co. v. Saco Brick Co. 198 Mass. 212, 218,219. Nor can a party, who has the choice between two courses of action, and chooses one with the means of full knowledge before him to which his attention is called, have relief on the ground that *362he made a miscalculation. Childs v. Stoddard, 130 Mass. 110, 112. The contract as it left the hands of the plaintiffs expressed exactly the intention of the defendant and the terms under which it consented to become bound.
The work, however, not having been finished within the time specified in the sixth article, the twenty-sixth paragraph of the bill states that under the eighteenth article the defendant claims the right to deduct from the amount of the contract price remaining due “the sum of seventy-five dollars ... for each and every calendar day beyond said time for the completion of the said work . . . until the said work shall be completed” “as liquidated damages, and in full compensation” for the delay covering a period of eight months. But the sixth article having stipulated that “the time in which the various portions and the whole of this contract are to be performed and the work is to be completed is of the essence of this contract,” which has never been waived by the defendant, no relief on that ground can be decreed. The intention of the parties having been clearly expressed, the amount thus ascertained cannot under the circumstances be treated as in the nature of a penalty or forfeiture. Wallis v. Carpenter, 13 Allen, 19. Cushing v. Drew, 97 Mass. 445, 446. Glynn v. Moran, 174 Mass. 233. Story Eq. Jur. (13th ed.) §§ 1315-1320.
It further is alleged that the defendant also “has assessed” and deducted damages for moneys paid to engineers and inspectors and for pumping, but these allegations are insufficient to maintain the bill. The remedy by an action at law is plain, efficient and exclusive. Holden v. Hoyt, 134 Mass. 181, 185. Fuller v. Percival, 126 Mass. 381, 383.
We are accordingly of opinion that the contract cannot be cancelled and the plaintiffs be allowed to recover the fair value of the labor and materials, and the decree sustaining the demurrer and dismissing the bill should be affirmed with costs.
So ordered.